You can display tooltip message in region, marker and text map using WP Geo map plugin. Follow below steps to display tooltip message of each location:

Show Tooltip Message

Step 1Go to Add or Edit Region Page.
Step 2Enter the Message in ‘Tooltip Message’ tab.

Tool Tip Message

Step 3Click on Save Region and open it in a browser. You’ll see the tooltip message on the location.

Live Example Show Tooltip Message For each Locations

World Map With Capitals

Video Tutorial